The present invention, in some embodiments thereof, relates to analysis of biopsy cores, and, more particularly, but not exclusively, to a method and system for automatically analyzing biopsy cores extracted from a plurality of respective biopsy locations in a prostate.
Based on recent statistics, for the general population, a man has about a 17 percent chance (1 in 6) of being diagnosed with prostate cancer at some point during his lifetime (lifetime risk), and a 3 percent chance (1 in 33) of dying from prostate cancer.
Current screening methods for symptomatic prostate-cancer (PCa) detection, such as digital rectal examination (DRE), transrectal ultrasound (TRUS) or prostate specific antigen blood test (PSA), lack sensitivity and specificity. For example, elevations in PSA occur not only in cancer cases but also in some non-neoplastic conditions, such as nodular hyperplasia (approx 25% PSA>4 ng/ml) and prostatitis, leading to a considerable overlap in levels of serum PSA between that found in such conditions and that found in prostate cancer patients (approx 80% PSA>4 ng/ml). If suspicious findings are present in any of these screening tests, a trans-rectal ultrasound guided needle-biopsy examination (TRNB) is practiced [American College of Physicians 1997]. The rate of negative (non-cancerous) findings for TRNB examination is about 75%, which indicates a high over-prescription of this highly invasive and costly examination. Furthermore, none of the above screening methods provide information on tumor differentiation and/or location and/or dimensions. The lack of location information, which could serve as guidance during the needle-biopsy examination, leads to high false-negative rates in TRNB (of ˜28% in the first examination and ˜17% in repeated ones).
Clearly, an improved method for screening, imaging and staging of prostate cancer, providing reliable information on the lesion's extension and site, as well as on its pathological stage, is required for the purpose of diagnosis as well as disease management (choice, monitoring and control of therapy). Numerous improvements of standard TRUS have been developed, such as the power Doppler imaging (DPI), the colour Doppler TRUS (CDUS) and the 3 dimensional Doppler (3DD). However, these modalities can not reliably provide information about the pathological stage of the lesions. Methodologies based on endo-rectal magnetic resonance imaging (ER-MRI) also exist but they are expensive and their use is limited to pre-operative staging.
Methods and devices for detection, localization and histological grading of PCa have been proposed (see PCT WO 2004/041060 to Breskin et al, filed Nov. 6, 2003), based on mapping the zinc concentration distribution within the prostate. The proposed non-invasive method consists of local x-ray irradiation of the gland, followed by the measurement of characteristic zinc emission with a trans-rectal X-Ray Fluorescence (XRF) probe.
Additional background art includes Zaichick et al., International Urology and Nephrology 28(5), 687-694, 1996; Zaichick et al., International Urology and Nephrology 29(5), 565-574, 1997; Habib et al., Br. J. Cancer 39 700-704, 1979; Costello et al., J. Inorg. Biochem. 78 161-165, 2000; Lahtonen R, The Prostate 6 177-183, 1985; Shilstein et al., J. Phys. Med. Biol. 49 1-15, 2004; Shilstein et al., Talanta 70 914-921, 2006; and Vartsky et al., J. Urol. 170 2258-2262, 2003.